The MG 45 differed from the MG 42 in that it did not completely lock its breech before firing, increasing its rate of fire and simplifying its construction. In 1945, the material shortages of the Third Reich led to the development of a newer version of the MG 42, the MG 45 (or MG 42V). This had a different operation mechanism that used delayed blowback as opposed to roller locking. For this reason, the MG 45 is considered a different type of firearm, as the mechanisms of these two guns are different. It used steel of lesser quality, with reduced weight to 9 kg, while retaining the horizontal cocking handle. First tests were undertaken in June 1944, but development dragged on and eventually only ten were built. The tested MG 45/42V fired 120,000 rounds in succession at a rate of fire around 1,350 rounds per minute. The MG 42V had some influence in the post-war development of roller-delayed blowback system, as employed in modern Heckler & Koch small arms.